Double ventricular response via dual atrioventricular nodal pathways resulting in sustained supraventricular nonreentrant tachycardia.

摘要

Supraventricular tachycardia caused by 1:2 atrioventricular conduction (atrial rate at a cycle length of about 680 milliseconds) was observed on the esophageal electrogram (Fig. 1), and double His bundle and ventricular responses was caused by simultaneous fast and slow AV nodal pathway conduction with each atrial wave (Fig. 2). The patient underwent successful slow pathway ablation with complete disappearance of symptoms and electrocardiographic manifestations of 1:2 AV conduction. Atrial fibrillation can be erroneously diagnosed in such patients when Wenckebach periodicity is present during fast and slow AV nodal pathway conduction (J Cardiovasc Electrophysiol. 2006;17:312.). Every sinus beat with concomitant junctional premature beat resulting in a bigeminal rhythm should be considered on the differential diagnosis of such a surface ECG, but consistent HV intervals and the satisfying results of slow pathway ablation make it untenable. ESO indicates esophagus electrogram; HRA, high right atrial electrogram; His, His bundle electrogram; CSp, proximal electrogram of coronary sinus; CSm, middle electrogram of coronary sinus; CSd, distal electrogram of coronary sinus.